Varicolored textile articles



Unite States Patent 3,375,651 VARICOLORED TEXTILE ARTHCLES Louis B. Greeson, .lr., Pensacola Beach, Fla., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware N0 Drawing. Filed May 31, 1966, Ser. No. 553,715 5 Claims. (Ci. 57153) The present invention relates to textile articles that exhibit a diversity of colors although they have been dyed in one operation. More particularly, the present invention relates to acid dyed textile fabrics and yarns exhibiting substantially white threads and deeply colored threads.

Fabrics made from varicolored threads have certain desired properties. To produce such parti-colored fabrics it is ordinarily necessary to dye the yarns separately from each other before they are woven or knitted into fabric. Obviously, such operation is quite expensive compared to one in which the fabric is dyed in a single system. Accordingly, it has long been desired in the textile industry to provide a fabric made throughout of generally the same synthetic polymer but when dyed would show a pronounced versicoloration. While much success has been attained by workers in this field, a satisfactory fabric showing substantially white threads and deeply colored threads of the same general polymer when acid dyed in one operation has not been disclosed to the art.

An object of the present invention is to provide an acid dyed textile mouline fabric.

Another object is to provide an acid dyed textile fabric made from polyamide polymers with some threads thereof being substantially white and other threads thereof being deeply colored.

Still another object is to provide a multi-strand yarn, at least one strand of which is white and at least another strand of which is deeply colored.

The manner in which these and other objects and features of the invention are attained will appear more fully from the following description thereof, in which reference is made to typical and preferred procedures in order to indicate more fully the nature of the invention, without intending to limit the invention.

The product according to this invention is a textile fabric, knitted, woven or otherwise made from synthetic linear polyamide yarns. After the fabric is made, it is dyed With an acid dye normally suitable for dyeing fabrics made from'polyamide yarn. This mouline fabric is made from two specifically different polyamide yarns. The first yarn is made from a polyamide polymer whose polymerization is controlled such that its polymer chain exhibits between and 30 gram-equivalents of titratable amine end groups per 10 grams of polymer. Preferably, the amine ends in the polymer of the first yarn is in the range of -28 groups per 10 grams of polymer. A second yarn composing the fabric is made from a polyamide polymer whose production is controlled such that the polymer chain is predominantly amine end terminated to the extent that it exhibits between 50 and 175 gram-equivalents of titratable amine end groups per 10 grams of polymer. In the fabric the yarn made from the polymer containing the inordinately low amount of amine end groups will be substantially white. On the other hand, the yarn containing the high amount of ami e end groups will present a deep color according to the specific dye employed. The two types of yarn can be associated together by plying, interlacing, braiding, etc., and when the composite product is dyed using an acid dye it will be multi-colored.

The first yarn composing the fabric or multi-strand yarn of the present invention and exhibiting the dye resistant property is made from polyamide-forming substances such as caprolactam and hexamethylene-diammonium adipate which are polymerized by conventional procedures except that the normal stoichiometric equivalence of reactants is adjusted such that a suitable excess of dicarboxylic acid is added to the polyamide-forming reactants some time before completion of the polymerization.

The yarn composing the fabric or multi-strand yarn but showing an enhanced acid dye receptivity is made from conventional polyamide-forrning reactants except that an additive or plurality of additives are added to the polyamide-forming sub-stances prior to the completion of the polymerization so as to insure that the resulting polymer has an unusually high amount of amine end groups.

By the expression titratable acid groups per 10 grams of polymer is meant the number of gram-equivalents of COOH ends per 10 grams of polymer as determined by the method of G. B. Taylor and J. E. Waltz, Analytical Chemistry, vol. 19, p. 448; (1947). Likewise, the expression titratable amine end groups per 10 grams of polymer is meant the number of gram-equivalents of NH ends per 10 grams of polymer as determined by the method described in the just-mentioned publication.

The polyamides as described herein can be basically obtained either by the self-polymerization of monoaminemonocarboxylic acids such as aminocaproic acid, or by reacting a diamine with a dibasic acid, such as hexamethylenediamine and adipic acid.

The following examples illustrate the invention.

Example I First, a dye resistant polyamide yarn was produced. A 50 percent aqueous solution of hexamethylenediammonium adipate (nylon 66 salt) was prepared by a conventional procedure and heated to a temperature of C. A suflicient amount of a 30 percent aqueous solution of adipic acid at 80 C. was added to the adipate solution to provide an excess of 2.2 mol percent of adipic acid based on the weight of the ultimate polyhexamethylene adiparnide polymer. The elevated temperature was employed because of the low solubility of adipic acid in water at relatively low temperatures.

Thereafter, a stainless steel autoclave adapted for batch polycondensation of polyhexamethylene adipamide (nylon 66) was charged With the resulting mixed solution. The temperature of the charge was C., and the pressure in the autoclave was 150 p.s.i.g. The contents in the autoclave then were heated quickly to a temperature of 200 C. under 250 p.s.i.g. pressure at which time a small amount of an aqueous slurry containing 30 weight percent TiO delustrant was added such that the ultimate polymer contained 2.0 percent TiO Heating of the contents was continued until the polyamide-forming material in the autoclave reached a temperature of 240 C. At this stage bleeding 0d of water vapor was begun to reduce the pressure in the autoclave to atmospheric pressure. During this pressure reduction the polymer temperature gradually was increased to 270 C. Upon completion of the poly condensation reaction, the polymer was extruded in the form of a ribbon onto a casting Wheel where it was quenched with Water. Thereafter, the ribbon was chipped into flakes. The flakes were melt spun and drawtwisted in a conventional manner to form a 40 total denier-13 filament yarn.

In a like manner, a dye receptive polymer was made following the procedure described in a copending application Ser. No. 307,315 filed Sept. 9, 1963, having common ownership herewith. In that application, there is described a procedure for producing a readily acid dyed polyamide by incorporating in the polyarnide during polycondensation a combination of additives which increases the titratable amine end groups in it. The combination of additives includes a small amount of phenylphosphiuic acid, a small amount of N-aminoethyl piperazine, particularly N-(2- aminoethyl) piperazine. The amount of phenylphosphinic acid incorporated in the polymer is usually about 0.05-1.0 percent based on the weight of the resultant polymer. The amount of N-aminoethyl piperazine incorporated in the polymer will be generally in the same range.

In this particular example sufficient amount of phenylphosphinic acid and N-(Z-aminoethyl) piperazine was added to the hexamethylene diammonium adipate undergoing polycondensation in the autoclave such that the ultimate polymer had equal amounts of each additive and a total additive content of 0.62 weight percent. The polymer was produced and spun into yarn in a manner identical to that just described for the dye resistant yarn.

The dye resistant yarn and the dye receptive yarn were knitted in alternate bands of a tricot fabric on a conventional knitting machine. The resulting greige fabric appeared uniformly white. The fabric was scoured and dyed under normal conditions using a typical acid dye solution used for synthetic fibers. In this case, the substance used was a dye stock composed of 5.0 grams Brilliant Alizarine Milling Blue BL, 0.4 gram of Xylene Light Yellow R., and 1.08 grams of Duronylite Red BLL. The dyed fabric exhibited bands of dark navy blue alternating with substantially white bands. Instrumental comparison by means of a spectrophotometer indicated that the dye resistant yarn was relatively unstained while the deep dye yarn had dye depth estimated to be 700 units darker. This was measured on a Colormaster Model V manufactured by Manufacturers Engineering and Equipment Corporation. The white yarn had gram-equivalents of titratable amine end groups per 10 grams of polymer. The yarn which was dyed navy blue showed 87 gram-equivalents of titratable amine end groups per 10 grams of polymer.

Example II Example III Dye resistant polymers were prepared as described in Example I but with various amounts of excess adipic acid. These polymers were converted into 40-13 dull (2.0 percent TiO yarns and knitted into fabric in bands adjacent to bands of the standard polyhexamethylene adipamide yarn of Example II. Results are indicated in the following table:

Mol Percent Dyed Fabric Appearance Excess Acid Dye Resist Standard 1. Pale Medium Blue. 1. 50 Almost White Do. 1. 80 White Do. 2.18 .do Do.

An addition of excess adipic acid above 3 mol percent depressed the polymer viscosity to a point that a satisfactory yarn could not be made.

Example IV As in Example I, a nylon 66 salt solution was prepared and heated to a temperature of 80 C. Suflicient 37 percent aqueous slurry of sebacic acid was then added thereto to provide 1.8 mol percent of sebacic acid based on nylon 66 salt for the production of yarn to be resistant to acid dyes. Because of the low solubility of sebacic acid in nylon 66 salt solution or in water, the additive dibasic acid was charged in the form of an aqueous slurry to the 4 hot salt solution. Normal heat and light stability additives and delustrants were then added; and the nylon salt solution was evaporated and polymerized following the operational procedure of Example I. The resultant polymer had i an RV (relative viscosity) of 21.6 with 26 amine end equivalents per million grams of polymer. The nylon 66 dye resist polymer was converted into 40-13 dull (2.0 percent TiO yarn by conventional melt spinning and drawtwisting operational procedures.

Example V As above, standard nylon 66 salt solution was prepared and heated to a temperature of C. Sufficient 33 percent aqueous solution of isophthalic acid was then added thereto to provide 1.8 mol percent of isophthalic acid based on nylon 66 salt for the production of yarn to be resistant to acid dyes. Because of the low solubility of isophthalic acid in nylon 66 salt solution or water, the additive was charged in the form of an aqueous slurry to the hot salt solution. Normal heat and light stability additives and delustrants were then added, and the nylon salt solution was evaporated and polymerized following the operational procedures of Example I. The resultant polymer had an RV of 21.2 with 28 amine end equivalents per mil- Example VI As above, standard nylon 66 salt solution was prepared 1 and heated to a temperature of 80 C. Enough 1,2,3,4- cyclopentanetetracarboxylic acid (CPTA) was added to give 0.9 percent CPTA based on nylon 66 salt and enough sebacic acid to give 0.9 mol percent sebacic acid based 1 on nylon 66 salt was also added, providing a total of 1.8 mol percent excess dibasic acid. These two acids were charged as a single aqueous solution at 80 C. The solution was charged to the hot salt solution to insure against precipitation. Normal heat and light stability additives and delustrants were then added, and the nylon salt solution was evaporated and polymerized following the operational procedure of Example I. The resultant polymer had an RV of 20.6 with 198 carboxyl and 24 amine end equivalents per million grams of polymer. The nylon 66 dye resist polymer was converted into 40-13 dull yarn by conventional melt spinning and drawtwisting operational procedures.

Example VII The dye resist nylon 66 yarns produced from polymers described in Examples I, IV, V, and VI were knit in successive bands into a tricot fabric with bands of deep dyeing yarn as previously described separating the bands of dye resist yarn. The resultant greige fabric appeared uniformly white. The fabric was scoured and dyed under normal conditions with the acid dye of Example I. The dyed fabric exhibited bands of dark navy blue alternating with essentially white bands composed of the dye resist yarns. Comparison indicated that the additives described in Examples IV, V, and VI were equivalent to adipic acid in providing acid dye resistance to the yarns in the knit fabric.

Example VIII Standard nylon 66 salt solution and sufiicient 1,2,3,4- cyclopentanetetracarboxylic acid (CPTA) to give 1.8 mol percent CPTA based on nylon 66 salt were charged to an autoclave and evaporated and polymerized according to the above-described procedure. The resultant polymer had an RV of 18.4 with 24 amine end equivalents per million grams of polymer. This polymer was resistant to acid dyes.

Example IX Standard nylon 66 salt solution and sufficient sebacic acid to give 1.8 mol percent sebacic acid based on the salt were charged to an autoclave and evaporated. The residue of evaporation was polymerized as above described. The resultant polymer had an RV of 14.5 with 19 amine end equivalents per million grams of polymer. Yarn spun from this polymer was resistant to acid dyes.

Example X As outlined in Example I, acid dye resistant polymer was prepared containing 1.8 mol percent excess adipic acid, and deep-dyeing polymer was also prepared. Each type of polymer contained 0.3 percent TiO to provide standard semi-dull luster. By conventional melt spinning operations each type of polymer was converted into the corresponding 40 denier-l3 filament yarns. Analysis showed that the acid dye resistant yarn contained 20 gram-equivalents of amine end groups and 192 gramequivalents of carboxyl end groups per grams of polymer, the corresponding end group analysis for the deep-dyeing yarn was 90 and 52, respectively, for amine and carboxyl end groups.

Four ends of the 40-13 dye resistant yarn were plied together and were texturized on a standard Whitin A.R.C.T., Type FT-F texturizer to provide characteristic false-twist heat-set texture. Four ends of deep-dyeing 40- 13 yarn were similarly plied and texturized. Each type of textured yarn was given approximately 75 turns per inch of twist by uptwisting, the total denier of the resultant yarns being about 185.

The plied, texturized yarns were then knit into a double-knit fabric on a Universal flat bed knitting machine, the deep-dyeing yarn comprising stripes inch wide separated by stripes A1 inch wide comprised of the acid dye resist yarn. In the greige the fabric appeared uniformly white. Samples of the fabric were dyed and finished using different colored acid dyes for each sample: dark red, black, dark brown, navy blue, and turquoise blue. The finished fabrics had a pleasant firm hand and excellent bulk and body, making them especially suitable for shirts, blouses, and skirts. The various color combinations were all very attractive visually; deep maroon stripes on White, black stripes on white, dark brown stripes on white, navy blue stripes on white, and turquoise stripes on white. In none of the fabrics did the dye resistant yarn comprising the White bands show any evidence of staining that would 6 have reduced the definition and contrast of the colored stripes.

It is seen from the above that the present invention provides numerous advantages. Among these is that the fabrics when dyed with standard acid dyestuffs in a single dye bath present a multicolored pattern. The dye resistant yarn portion is white or of much lighter color than the other yarn components. By this means color-patterned fabrics of great variety are readily made by piece-dyeing in a single dye bath.

It is, of course, understood that various changes may be made in the product and process above-described without departing from the spirit of the invention as defined in the claims.

What is claimed is:

1. An acid dyed textile mouline fabric made of an acid dye resistant substantially white first yarn composed of a synthetic linear polyamide having between 15 and 30 gram-equivalents of titratable amine end groups per 10 grams of polymer and a second yarn deeply colored with an acid dye and composed of a polyamide having between and gram-equivalents of titratable amine end groups per 10 grams of polymer.

2. The fabric of claim 1 wherein the polyamide is polyhexamethylene adipamide.

3. The fabric of claim 2 wherein the polymer composing the deeply colored yarn has incorporated therein a dye-enhancing amount of phenylphosphinic acid and N- aminoethyl piperazine.

4. The fabric of claim 1 wherein the polyamide is polycaprolactam.

5. A yarn composed of multi-strands, at least one substantially white strand of which is composed of a synthetic linear polyamide having between 15 and 30 gramequivalents of titratable amine end groups per 10 grams of polymer, and at least another strand of which is deeply colored with an acid dye and is composed of a polyamide having between 50 and 175 gram-equivalents of titratable amine end groups per 10 grams of polymer.

No references cited.

JOHN PETRAKES, Primary Examiner. 

5. A YARN COMPOSED OF MULTI-STRANDS, AT LEAST ONE SUBSTANTIALLY WHITE STRAND OF WHICH IS COMPOSED OF A SYNTHETIC LINEAR POLYAMIDE HAVING BETWEEN 15 AND 30 GRAMEQUIVALENTS OF TITRATABLE AMINE END GROUPS PER 1006 GRAMS OF POLYMER, AND AT LEAST ANOTHER STRAND OF WHICH IS DEEPLY COLORED WITH AN ACID DYE AND IS COMPOSED OF A POLYAMIDE HAVING BETWEEN 50 AND 175 GRAM-EQUIVALENTS OF TITRATABLE AMINE END GROUPS PER 106 GRAMS OF POLYMER. 